Control systems for controlling the operation of mobile material distribution apparatus have been known for some time. Generally, these control systems are used to control the rates at which various products are dispersed or distributed. Exemplary applications where such control systems have been used include the control of farm machinery and implements such as sprayers and planters, and the control of public works vehicles such as salt spreaders for road maintenance and the like. U.S. Pat. Nos. 4,630,773 and Re. 35,100, which are both hereby incorporated by reference, disclose the use of microprocessor based control systems wherein the ground speed and the precise field position of the distribution apparatus, as well as the type of soil and other factors are monitored and employed to distribute a controlled amount of material throughout a field in farming applications.
Prior art control systems have suffered from certain drawbacks. For example, early control systems were dedicated products designed for use with a specific implement or machine having a specific application. Under such an approach, it is necessary to have a dedicated control system for each material distribution apparatus owned. Thus, if a farmer utilizes both a sprayer and a planter on his/her farm, that farmer would require a dedicated control system for each of these two implements. As a result, the end user incurred excessive costs in both purchasing and maintaining two separate control systems as well as in providing training for multiple systems if more than one type of control system is employed.
Efforts have been made to produce universal control systems which can be used with more than one kind of material distribution apparatus. U.S. Pat. No. 4,803,626 and U.S. Pat. No. 4,924,418, which are both hereby incorporated by reference, disclose monitoring and control systems which achieve such universality. However, control systems such as these are generally disposed within the cab of the vehicle they service. Not only does this result in excessive wiring within the cab, but it also makes switching between implements onerous, if not impossible.
More specifically, control systems typically require numerous inputs from sensors and actuators disposed on the implements they control. In order to switch from one implement to another, numerous cables must be disconnected and others must be connected, thereby causing both time delays and the possibility of poorly connected and/or incorrectly connected wiring. Even after such wiring is completed correctly, prior art control systems require substantial software changes and configuration adjustments to adapt the system to the newly attached material distribution apparatus. Thus, switching between distribution devices with a single control system has often been difficult and time consuming.
While some prior art systems reduced the amount of wiring in the cab by using a serial bus to connect system components, such as the system described in U.S. Pat. No. 5,260,875, which is incorporated by reference herein, such systems lack a universal terminal, thus requiring hardware changes in order to effect a change in system application.
Prior art control systems have suffered from additional drawbacks. For example, although prior art systems have had the ability to control and monitor the operation of booms in farming applications, this control has been very limited. More specifically, a boom is an elongated distribution tube usually positioned in a horizontal plane parallel to the ground, and having a plurality of nozzles or, in the case of booms for granular applications, distribution ports spaced along its length. Typically, a product to be dispensed is pumped into the elongated tube which delivers the product to the nozzles (or distribution ports) which, in turn, distribute the product onto the surface to be treated.
Prior art control systems have had the capability of monitoring the operating state of the nozzles/distribution ports (i.e., open or closed), and, depending upon those operating states, adjusting the amount of product delivered to the tube to regulate the dispersal of the product to the field. However, these prior art systems did not monitor which of the nozzles/distribution ports were open or closed. These same systems often employ the global positioning system ("GPS") to monitor the amount of dispersant applied across a surface and to create a mapped record of such amounts. By ignoring which of the boom nozzles/distribution ports are open and which are closed, these prior art systems necessarily resulted in inaccurate GPS maps; overestimating amounts in areas where the boom nozzles/distribution ports were off during a second run across a previously treated area, and failing to note missed swaths during a first run.
Moreover, in some instances booms include two fence row nozzles, one at each opposite end of the elongated distribution tube. In other instances, booms include only a single fence row nozzle disposed at one of its ends. Fence row nozzles usually have twice the capacity of the other nozzles on the boom and are typically used to spray the outer edge of a field, ditch bank or fence row adjacent to the field being serviced. Prior art control systems have ignored these fence row nozzles altogether. Thus, when one or more fence row nozzles are in use, the application rate selected by the control system for the product being dispersed can be inaccurate. In addition, since prior art control systems ignore the fence row nozzles, the material dispersed therethrough will not be recorded by GPS and the GPS maps will be inaccurate.
Prior art control systems have also provided limited alarm systems. For example, when an error occurred, these systems typically would display a cryptic code on a display and would make an audible sound. The sound was typically the same regardless of the error. Thus, the audible error information provided by these systems provided no indication of the nature of the error. Further, the error message usually disappeared from the LCD within a relatively short period of time and was gone forever. Therefore, if the user did not read the error message within a relatively short time after the audible alarm sounded, he/she would never know the nature of the error message.